A summer exhibition series between two European football clubs featuring South Korean stars in their native country remained up in the air Friday, due to a scheduling conflict with the domestic league.

Local promoters Untouchable Sports Group (USG) and Stadium X are planning a two-match series between the Italian champions Napoli, led by South Korean defender Kim Min-jae, and the Spanish side RCD Mallorca, featuring popular South Korean midfielder Lee Kang-in. They announced earlier this month that they were seeking to hold matches on June 8 in Seoul and June 10 in Goyang, just northwest of the capital city.

However, the Korea Professional Football League (K League), which oversees professional football in the country, is opposed to holding the Napoli-Mallorca game on June 10, citing three matches in the top-flight K League 1 also scheduled that day.

The two sides have held multiple meetings in recent days but have not been able to narrow their differences, a K League official said Friday.

"We met with USG and Stadium X officials yesterday and we have told them that it is not possible to have the second exhibition match on June 10," the league official said, requesting anonymity.

Foreign clubs hoping to hold matches in South Korea during the K League season require approval from the domestic league.

USG and Stadium X have countered that the K League is being unfair to Napoli and Mallorca, since the league has already allowed Manchester City and Atletico Madrid to play here on July 30, when two matches in the second-tier K League 2 are scheduled.

The K League has stated that it is not opposed to exhibition matches by European clubs in principle but that it wants to keep the spotlight solely on the top-division clubs in June, with the season in full swing.

The K League 1 will be on an All-Star break in the final week of July, which opened the doors for the Man City-Atletico Madrid match, the K League explained.

An official with USG said it had not yet been determined whether the two companies would go ahead with just the one match on June 8 or would not have any Napoli-Mallorca game here, period.

Per said official, the K League has asked the companies to pay a certain amount as a deposit, in order to make sure they have the financial means to run the matches.

"We don't want to be in a situation where we've given them the green light and then find out they can't afford to operate these events," the official said. "Once we get a response from them, we will have more discussions internally and then make the decision early next week." (Yonhap)